Anthro2050 1st Edition Lecture 12 Outline of Last Lecture I. Non Mendelian Genetics Outline of Current Lecture II. Evolutionary Forces & Sources of Variation III. Introduction to Primates Current Lecture Variation is the raw material that evolution acts on Individual variation: Independent assortment, crossing over, and mutation Mutation- the only thing that produces new variations, everything else is just the reshuffling of existing variations. Mutation is a copying error when DNA is replicated. Point Mutation- the changing of a single nucleotide Deletion- inserting & taking out of nucleotides Mutations can be 'good' or 'bad', but most are just neutral. Actual rates of mutation are difficult to determine, considering that the majority are neutral and that 70% of pregnancies end in miscarriage. (Only 15% occur when the mother knows she is pregnant, the 70% is for all pregnancies, known and unknown) The rough estimate is, there are between 1 to 100 mutations per 1 million sex cells. While neutral mutations have no real effects, if a mutation is bad, it can be harmful. - Population Variation: natural selection, genetic drift, gene flow. The ways variation leads to evolution. Gene Flow- through immigrants from one population to another, introducing new alleles to a population. Genetic Drift- random sampling and fluctuating of gene frequencies from one generation to the next. Seen frequently in very small populations. Founder Effect- a small subset of a population breaks off to make their own population. Suddenly, and traits not in these individuals are not in the new populations, and traits they do have become more common than in the original population These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.